• Kyungpook Mathematical Journal
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• v.46 no.3
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• pp.433-436
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• 2006

In this note we show that a representable difference algebra is equivalent to a commutative BCK-algebra.

• Bulletin of the Korean Mathematical Society
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• v.61 no.3
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• pp.813-823
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• 2024

In this paper, we prove that every 2-local derivation on several classes of C^*-algebras, such as unital properly infinite, type I or residually finite-dimensional C^*-algebras, is a derivation. We show that the following statements are equivalent: (1) every 2-local derivation on a C^*-algebra is a derivation, (2) every 2-local derivation on a unital primitive antiliminal and no properly infinite C^*-algebra is a derivation. We also show that every 2-local derivation on a group C^*-algebra C^*(𝔽) or a unital simple infinite-dimensional quasidiagonal C^*-algebra, which is stable finite antiliminal C^*-algebra, is a derivation.

• Journal of Educational Research in Mathematics
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• v.12 no.3
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• pp.353-369
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• 2002

In this paper, we deal with the teaching of the approaching to algebra based on patterns. The change of algebra curriculum has been undergoing in many countries including USA, England, Australia. The traditional algebra curriculum starts with letters(variables), algebraic expressions, and equations. But these formal approaching method has many difficulties in teaching school algebra. Therefore the new algebra curriculum has to be needed, and the approaching to algebra based on patterns has been focused. In this paper, we compare this new approaching to algebra based on patterns to the traditional algebra curriculum. Next we consider the NCTM algebra curriculums based on Standards (1989) and Standards 2000(2000), Britannica textbook series(1998) based on RME. Also we investigate our pattern approaching in our curriculum and discuss some problems from the perspective of the approaching to algebra based on patterns.

• Journal of the Korean School Mathematics Society
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• v.11 no.1
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• pp.133-157
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• 2008

This paper is based on theory of Usiskin who defined inclusively the various concepts of algebra among many theories classifying a type of the algebra. For this purpose, we examined the curriculum of the algebra of Korea, America and Japan, then analyzed where the problems in "Letter and Formula" of the textbooks fall under Usiskin's concepts of algebra.

• Bulletin of the Korean Mathematical Society
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• v.61 no.1
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• pp.217-227
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• 2024

Let G be an infinite countable group and A be a finite set. If Σ ⊆ A^G is a strongly irreducible subshift of finite type and 𝓖 is the local conjugacy equivalence relation on Σ. We construct a decreasing sequence 𝓡 of unital C^*-subalgebras of C(Σ) and a sequence of faithful conditional expectations E defined on C(Σ), and obtain a Toeplitz algebra 𝓣 (𝓡, 𝓔) and a C^*-algebra C^*(𝓡, 𝓔) for the pair (𝓡, 𝓔). We show that C^*(𝓡, 𝓔) is *-isomorphic to the reduced groupoid C^*-algebra C^*_r(𝓖).

• Journal of Elementary Mathematics Education in Korea
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• v.22 no.2
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• pp.115-142
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• 2018

This research analyzed domestic researches on early algebra education which are published in six major mathematics education journals in Korea. The purpose of this work is to grasp trends of early algebra education in Korea and to draw up future tasks. From 2000 to 2017, 89 papers which are related to early algebra education published in 6 journals. The 89 papers were categorized by research period, academic journals, research topics, and research subjects. As a result, the number of researches on early algebra education in Korea has increased since 2000. Although early algebra education belongs to the field of elementary mathematics education, lots of papers were published in other math education journals than in the math education journals for elementary school mathematics. Most research focused on proportional reasoning across the algebraic content area. The majority of the research subjects were students, especially upper-grade students of elementary school. Based on the results of this study, some implications for early algebra education in Korea were suggested.

• School Mathematics
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• v.9 no.3
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• pp.409-426
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• 2007

The relevance of secondary school algebra focused on paper and pencil manipulation has been reconsidered along with the expansion of universal education and the development of ICT such as computer or calculators. This study was designed to investigate the issues and trends of the recent algebra so as to provide implementations for algebra curriculum in Korea. The focus of algebra education has being shifted from paper pencil manipulation to algebraic thinking. The early algebra or informal algebra is one of the important traits of revolution, and the role of ICT is integrated in newly developed curricula. In Korea, algebra education has been retaining the traditional line even though the national curriculum documents allows ICT for instruction. The reasons of these discrepancies were analyzed and the tasks for the new curriculum in accordance with the current trends were suggested in this paper.

• Journal of Educational Research in Mathematics
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• v.12 no.1
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• pp.29-48
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• 2002

The purpose of this paper is to investigate the transfer in mathematics learning, especially focussing on arithmetic and algebra. There are many obstacles at the stage of transfer in learning. In the case of mathematics, each learning contents are definitely categorized by the learning level, therefore these obstacles are more happened than other subjects. First of all, this paper investigates the historical transfer from arithmetic to algebra by Sfard's perspectives. And we define prealgebra as the stage between arithmetic and algebra, which may be revised obstacles or misconceptions happened in the early algebra learning. Also, this paper discusses various obstacles and concrete examples happened in the transfer from arithmetic to algebra. To advance the understanding in the learning of algebra, we consider the core contents of the algebra learning which should be stressed at the prealgebra stage. Finally we present the teaching units of (pre)algebra which are sequenced from the variable concepts to equations.

• Research in Mathematical Education
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• v.9 no.4 s.24
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• pp.317-328
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• 2005

The aim of this study is to investigate future teachers' skills that can make problem solving methods concrete for 7-11 year old students. For the students in the concrete operations level, solutions of word problems should also be taught by concreting. But most of teacher candidates can not solve the problems without algebra because they got used to solve the word problems with algebra during their high school and university education. In this study, whether the teacher candidates have the skills of solving the primary school level problems without using algebra or not are being observed. At the end of this observation it is determinated that primary level teacher candidates generally prefer using algebra operations because of their former habits. The results show that in the education of the primary level teacher candidates, there is the need of developing the solving skills using figures and diagrams without algebra rather than algebraic solutions in word problems.

• Journal of the Korean School Mathematics Society
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• v.12 no.1
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• pp.99-114
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• 2009

Although they are interested in Linear Algebra not only in science and engineering but also in humanities and sociology recently, a study of teaching linear algebra is not relatively abundant because linear algebra was taken as basic course in colleges just for 20-30 years. However, after establishing The Linear Algebra Curriculum Study Group in January, 1990, a variety of attempts to improve teaching linear algebra have been emerging. This article looks into series of studies related with teaching matrix. For this the method for teaching the concepts of matrix in relation to historico-genetic principle looking through the process of the conceptual development of matrix-determinants, matrix-systems of linear equations and linear transformation.